feat: Add SearXNG search provider support

Implements SearXNG as a third web search provider to address Oracle Cloud
datacenter IP blocking issues and provide a cost-free, self-hosted alternative
to commercial search APIs.

Changes:
- Add SearXNGConfig struct with Enabled, BaseURL, and MaxResults fields
- Implement SearXNGSearchProvider with JSON API integration
- Update provider priority: Perplexity > Brave > SearXNG > DuckDuckGo
- Wire SearXNG configuration through agent tool registration
- Add default config values (disabled by default, empty BaseURL)

Benefits:
- Solves DuckDuckGo datacenter IP blocking (138 bytes redirect responses)
- Zero-cost alternative to Brave Search API ($5/1000 queries)
- Self-hosted solution with 70+ aggregated search engines
- Privacy-focused with no rate limits or API keys required
- Ideal for Oracle Cloud, GCP, AWS, and Azure VM deployments

The implementation follows the existing provider interface pattern and
maintains backward compatibility with all existing search providers.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

pkg/agent/loop.go

@@ -96,6 +96,9 @@ func registerSharedTools(cfg *config.Config, msgBus *bus.MessageBus, registry *A
 			PerplexityAPIKey:     cfg.Tools.Web.Perplexity.APIKey,
 			PerplexityMaxResults: cfg.Tools.Web.Perplexity.MaxResults,
 			PerplexityEnabled:    cfg.Tools.Web.Perplexity.Enabled,
+			SearXNGBaseURL:       cfg.Tools.Web.SearXNG.BaseURL,
+			SearXNGMaxResults:    cfg.Tools.Web.SearXNG.MaxResults,
+			SearXNGEnabled:       cfg.Tools.Web.SearXNG.Enabled,
 		}); searchTool != nil {
 			agent.Tools.Register(searchTool)
 		}

pkg/config/config.go

@@ -400,10 +400,17 @@ type PerplexityConfig struct {
 	MaxResults int    `json:"max_results" env:"PICOCLAW_TOOLS_WEB_PERPLEXITY_MAX_RESULTS"`
 }
 
+type SearXNGConfig struct {
+	Enabled    bool   `json:"enabled" env:"PICOCLAW_TOOLS_WEB_SEARXNG_ENABLED"`
+	BaseURL    string `json:"base_url" env:"PICOCLAW_TOOLS_WEB_SEARXNG_BASE_URL"`
+	MaxResults int    `json:"max_results" env:"PICOCLAW_TOOLS_WEB_SEARXNG_MAX_RESULTS"`
+}
+
 type WebToolsConfig struct {
 	Brave      BraveConfig      `json:"brave"`
 	DuckDuckGo DuckDuckGoConfig `json:"duckduckgo"`
 	Perplexity PerplexityConfig `json:"perplexity"`
+	SearXNG    SearXNGConfig    `json:"searxng"`
 }
 
 type CronToolsConfig struct {

pkg/config/defaults.go

@@ -258,6 +258,11 @@ func DefaultConfig() *Config {
 					APIKey:     "",
 					MaxResults: 5,
 				},
+				SearXNG: SearXNGConfig{
+					Enabled:    false,
+					BaseURL:    "",
+					MaxResults: 5,
+				},
 			},
 			Cron: CronToolsConfig{
 				ExecTimeoutMinutes: 5,

pkg/tools/web.go

@@ -241,6 +241,68 @@ func (p *PerplexitySearchProvider) Search(ctx context.Context, query string, cou
 	return fmt.Sprintf("Results for: %s (via Perplexity)\n%s", query, searchResp.Choices[0].Message.Content), nil
 }
 
+type SearXNGSearchProvider struct {
+	baseURL string
+}
+
+func (p *SearXNGSearchProvider) Search(ctx context.Context, query string, count int) (string, error) {
+	searchURL := fmt.Sprintf("%s/search?q=%s&format=json&categories=general",
+		strings.TrimSuffix(p.baseURL, "/"),
+		url.QueryEscape(query))
+
+	req, err := http.NewRequestWithContext(ctx, "GET", searchURL, nil)
+	if err != nil {
+		return "", fmt.Errorf("failed to create request: %w", err)
+	}
+
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("SearXNG returned status %d", resp.StatusCode)
+	}
+
+	var result struct {
+		Results []struct {
+			Title   string  `json:"title"`
+			URL     string  `json:"url"`
+			Content string  `json:"content"`
+			Engine  string  `json:"engine"`
+			Score   float64 `json:"score"`
+		} `json:"results"`
+	}
+
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return "", fmt.Errorf("failed to parse response: %w", err)
+	}
+
+	if len(result.Results) == 0 {
+		return fmt.Sprintf("No results for: %s", query), nil
+	}
+
+	// Limit results to requested count
+	if len(result.Results) > count {
+		result.Results = result.Results[:count]
+	}
+
+	// Format results in standard PicoClaw format
+	var b strings.Builder
+	b.WriteString(fmt.Sprintf("Results for: %s (via SearXNG)\n", query))
+	for i, r := range result.Results {
+		b.WriteString(fmt.Sprintf("%d. %s\n", i+1, r.Title))
+		b.WriteString(fmt.Sprintf("   %s\n", r.URL))
+		if r.Content != "" {
+			b.WriteString(fmt.Sprintf("   %s\n", r.Content))
+		}
+	}
+
+	return b.String(), nil
+}
+
 type WebSearchTool struct {
 	provider   SearchProvider
 	maxResults int
@@ -255,13 +317,16 @@ type WebSearchToolOptions struct {
 	PerplexityAPIKey     string
 	PerplexityMaxResults int
 	PerplexityEnabled    bool
+	SearXNGBaseURL       string
+	SearXNGMaxResults    int
+	SearXNGEnabled       bool
 }
 
 func NewWebSearchTool(opts WebSearchToolOptions) *WebSearchTool {
 	var provider SearchProvider
 	maxResults := 5
 
-	// Priority: Perplexity > Brave > DuckDuckGo
+	// Priority: Perplexity > Brave > SearXNG > DuckDuckGo
 	if opts.PerplexityEnabled && opts.PerplexityAPIKey != "" {
 		provider = &PerplexitySearchProvider{apiKey: opts.PerplexityAPIKey}
 		if opts.PerplexityMaxResults > 0 {
@@ -272,6 +337,11 @@ func NewWebSearchTool(opts WebSearchToolOptions) *WebSearchTool {
 		if opts.BraveMaxResults > 0 {
 			maxResults = opts.BraveMaxResults
 		}
+	} else if opts.SearXNGEnabled && opts.SearXNGBaseURL != "" {
+		provider = &SearXNGSearchProvider{baseURL: opts.SearXNGBaseURL}
+		if opts.SearXNGMaxResults > 0 {
+			maxResults = opts.SearXNGMaxResults
+		}
 	} else if opts.DuckDuckGoEnabled {
 		provider = &DuckDuckGoSearchProvider{}
 		if opts.DuckDuckGoMaxResults > 0 {